Note: This bug is displayed in read-only format because the product is no longer active in Red Hat Bugzilla.
For bugs related to Red Hat Enterprise Linux 5 product line. The current stable release is 5.10. For Red Hat Enterprise Linux 6 and above, please visit Red Hat JIRA https://issues.redhat.com/secure/CreateIssue!default.jspa?pid=12332745 to report new issues.

Bug 510008

Summary: [Emulex 5.4 bug] Lower throughput seen on be2net with MSIx interrupt
Product: Red Hat Enterprise Linux 5 Reporter: Subbu Seetharaman <subbu.seetharaman>
Component: kernelAssignee: Andy Gospodarek <agospoda>
Status: CLOSED ERRATA QA Contact: Red Hat Kernel QE team <kernel-qe>
Severity: high Docs Contact:
Priority: high    
Version: 5.4CC: andriusb, bobby.suber, dzickus, laurie.barry, lwang, mgahagan, peterm, sandy.garza, sean.murphy, syeghiay, tcamuso
Target Milestone: rcKeywords: OtherQA, Regression
Target Release: 5.4   
Hardware: All   
OS: Linux   
Whiteboard:
Fixed In Version: Doc Type: Bug Fix
Doc Text:
Story Points: ---
Clone Of: Environment:
Last Closed: 2009-09-02 08:15:26 UTC Type: ---
Regression: --- Mount Type: ---
Documentation: --- CRM:
Verified Versions: Category: ---
oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
Embargoed:
Bug Depends On:    
Bug Blocks: 461676    
Attachments:
Description Flags
patch to fix the perfoemance problem seen with MSIx. none

Description Subbu Seetharaman 2009-07-07 12:08:53 UTC
Description of problem:

Further testing of the fix for Bug 508839, we see that with MSIx interrupts, throughtput is significantly lower.

Version-Release number of selected component (if applicable):

el5.156 + be2net with patch for Bug 508839.

How reproducible:

Everytime

Steps to Reproduce:
Start RX on both ports using chariot uisng 10 1Gb clinets on each port or one 10Gb server on both ports.

  
Actual results:

Traffic starts at few Gbps; but within seconds drops to 2 Gbps

Expected results:

Should sustain 9+ Gbps on each port.

Additional info:

The problem is a side effect of the fix the fix for Bug 508839.  We have a fix that we are testing now.

Comment 1 Andrius Benokraitis 2009-07-07 14:44:58 UTC
Subbu - is this the final issue found during testing?

Comment 2 Subbu Seetharaman 2009-07-08 12:44:10 UTC
There are no other known issues.  We a few more test cases left.

We have a fix ready for this problem; but since some of the patches that I had uploaded earlier are not yet applied, I am not sure what source base should this patch be against.  Should I wait for the earlier patches to be applied ?  Please let me know.

Thanks.

Subbu

Comment 3 Subbu Seetharaman 2009-07-08 12:58:38 UTC
Never mind.  Looks like all changes have been applied to 157 source.  We will make the patch relative to source in 157.

Subbu

Comment 4 Subbu Seetharaman 2009-07-09 13:01:26 UTC
Created attachment 351068 [details]
patch to fix the perfoemance problem seen with MSIx.

This patch fixes a problem where with MSIX where we may return without clearing interrupt which will cause us to return to ISR bringing performance down due to too many interrupts.

This bug was introduced as part of the changes to fix for 508839.  This problem does not exist in the upstream driver and hence will not be submitted to upstream.

Subbu

Comment 6 RHEL Program Management 2009-07-10 19:03:24 UTC
This request was evaluated by Red Hat Product Management for inclusion in a Red
Hat Enterprise Linux maintenance release.  Product Management has requested
further review of this request by Red Hat Engineering, for potential
inclusion in a Red Hat Enterprise Linux Update release for currently deployed
products.  This request is not yet committed for inclusion in an Update
release.

Comment 8 Don Zickus 2009-07-14 20:58:19 UTC
in kernel-2.6.18-158.el5
You can download this test kernel from http://people.redhat.com/dzickus/el5

Please do NOT transition this bugzilla state to VERIFIED until our QE team
has sent specific instructions indicating when to do so.  However feel free
to provide a comment indicating that this fix has been verified.

Comment 10 Subbu Seetharaman 2009-07-16 12:13:46 UTC
Fix verified in kernel-2.6.18-158.el5.

Comment 12 errata-xmlrpc 2009-09-02 08:15:26 UTC
An advisory has been issued which should help the problem
described in this bug report. This report is therefore being
closed with a resolution of ERRATA. For more information
on therefore solution and/or where to find the updated files,
please follow the link below. You may reopen this bug report
if the solution does not work for you.

http://rhn.redhat.com/errata/RHSA-2009-1243.html

Comment 13 laurie barry 2009-09-02 13:27:12 UTC
Andrius,

Was this bug fixed for RHEL5.4 GA or redirected to a post RHEL5.4 errata kernel?

Laurie

Comment 14 Andrius Benokraitis 2009-09-02 15:40:21 UTC
This was fixed in RHEL 5.4 GA. (included in Snapshot 3)